This invention relates generally to a data storage tape cartridge and more particularly to a three-piece tape reel assembly with integrated driving teeth and/or with metal hub flanges.
Cartridges have been used for decades in the computer, audio and video fields. The data storage tape cartridge continues to be an extremely popular form for recording large volumes of information for subsequent retrieval and use.
The data storage tape cartridge generally consists of an outer shell or housing maintaining at least one tape reel assembly and a length of magnetic storage tape. The storage tape is wrapped about a hub portion of a tape reel and is driven through a defined path by a driving system. The housing normally includes a separate cover and base, the combination of which forms an opening (or window) at a forward portion thereof for allowing access to the storage tape by a read/write head upon insertion of the data storage tape cartridge into a tape drive. This interaction between the storage tape and head may take place within the housing, or the storage tape may be directed away from the housing to an adjacent area at which the read/write head is located. Where the tape cartridge/drive system is designed to direct the storage tape away from the housing, a single tape reel assembly is normally employed. Conversely, when the tape cartridge/drive system is designed to provide head/storage tape interaction within or very near the housing, a two or dual-tape reel assembly configuration is typically utilized.
The tape reel assembly has typically been of two designs. The first is a three-piece assembly and the second is a two-piece assembly. The three-piece tape reel assembly includes a first flange member operatively connected to a second flange member by a hub. The second flange member will typically have teeth formed therein for connecting to a drive. In such a three-piece assembly, the flanges are able to be kept flatter because the hub is not formed as a portion of one of the flanges. However, one of the drawbacks of such a design is that the teeth are not directly coupled to the hub. The teeth are connected to the second flange and the flange in turn is connected to the hub. Therefore, backlash is possible and this will provide degradation in the concentricity of the winding surface.
In the two-piece tape reel assemblies, there is a first generally flat flange which is operatively connected to a second flange that has the hub integrally formed thereto. The teeth are formed in the second flange which has the hub formed as a portion thereof In such a construction, the hub is directly coupled to the teeth and there is no backlash problem. However, it is difficult to maintain the flatness of the second flange due to the hub being formed as a portion of the second flange. Also, because the hub is formed as a portion of the second flange, the stiffness throughout the tape reel, along the hub from the second flange to the first flange, varies as the tape cartridge is stiffer proximate the second flange and hub causing an asymmetrical collapse on the hub as the tape is wound.
With respect to both of the configurations noted above, the inherent flatness of a plastic spool flange is limited and this effects the precision that can be obtained on the flange-to-flange spacing. This out of flatness also may lead to servo errors as the part rotates in a drive. The flanges that are made of plastic are therefore of limited flatness and also limited stiffness. A stiffer flange would guard against damaging the tape edges during handling.
Further, with respect to both designs, the flanges are secured to the hub such that the flanges adversely impact the collapse of the hub when the tape is wound.
The present invention addresses the problems associated with the prior art data storage tape cartridges.
In one embodiment, the invention is a tape reel assembly for a data storage tape cartridge. The tape reel assembly includes a discrete first flange and a discrete second flange. A discrete tape hub having a first and second side as the first flange operatively connected to the first side of the hub and the second flange operatively connected to the second side of the hub. The second side of the hub has a plurality of teeth directly connected thereto.
In another embodiment, the invention is a tape reel assembly for a data storage tape cartridge. The tape reel assembly comprises a first and second flange. A tape hub has a first side and a second side, the first flange operatively connected to the first side of the hub and the second flange operatively connected to the second side of the hub. A plurality of driving teeth are operatively connected to the hub. One of the flanges is operatively connected to the hub, wherein said one of the flanges is axially held in place to the hub and allows for lateral movement with respect to the hub.
In another embodiment, the invention is a tape reel assembly for a data storage tape cartridge. The tape reel assembly includes a discrete first flange, a discrete second flange, and a discrete tape hub having a first side and a second side. The first flange is operatively connected to the first side of the hub and the second flange is operatively connected to the second side of the hub. The second side of the hub has a plurality of driving teeth directly connected thereto. One of the flanges is operatively connected to the hub wherein said one of the flanges is axially held in place to the hub and allows for lateral movement with respect to the hub.